I ran my own self-hosted email server from 2008-ish to 2018, and I would highly recommend against doing it! Especially when Fastmail and Proton are so cheap.
I was running Postfix+Dovecot+Seive+SpamAssassin+Fail2ban+certbot+spf+dkim+reverse-ip+<other random crap>
It worked! Receiving email was overall pretty easy. I know I also did things the "hard way" by ad-hoccing all that together, and today there are a lot more out-of-the-box solutions that do all that for you. But still. Being a full-time email administrator is a job I will never do again unless I'm getting paid for it.
You know what really sucked? Deliverability. Frequently, emails I would send would just ... vanish ... no warnings, no errors, no failures. From my end, everything was perfect. Until days later, people would follow up with me and say, "Are you going to send that email?" ...
I had a business IP (Comcast Business). The IP address was clean, not black listed anywhere, not on SORBS or other lists. Still, successfully delivering an email was like 50/50, with no way to confirm the other party actually got it.
I was running Postfix+Dovecot+Seive+SpamAssassin+Fail2ban+certbot+spf+dkim+reverse-ip+<other random crap>
It worked! Receiving email was overall pretty easy. I know I also did things the "hard way" by ad-hoccing all that together, and today there are a lot more out-of-the-box solutions that do all that for you. But still. Being a full-time email administrator is a job I will never do again unless I'm getting paid for it.
You know what really sucked? Deliverability. Frequently, emails I would send would just ... vanish ... no warnings, no errors, no failures. From my end, everything was perfect. Until days later, people would follow up with me and say, "Are you going to send that email?" ...
I had a business IP (Comcast Business). The IP address was clean, not black listed anywhere, not on SORBS or other lists. Still, successfully delivering an email was like 50/50, with no way to confirm the other party actually got it.